The research program of this laboratory deals with the isolation, properties and biological activities of proteins associated with DNA in the chromosomes of higher organisms. Particular emphasis is placed on reactions which modify protein structure after synthesis is completed - such as acetylation, methylation and phosphorylation of histones and other nuclear proteins. The chemical and enzymatic basis of these reactions, and their results in terms of DNA-protein interactions are a major topic of investigation. Related projects deal with the events occurring at times of gene activation in cells stimulated by hormones or mitogenic agents, with particular attention to changes in nuclear phosphoprotein composition or metabolism.